1. Technical Field
The present invention relates to a liquid storing body for supplying a liquid containing a sedimentous component such as pigment to a liquid jetting apparatus.
2. Related Art
Inkjet printers (liquid jetting apparatus) that use pigment ink (liquid) are known. In pigment ink, pigment is dispersed as particles in a solvent, and therefore if an ink tank or an ink pack (liquid storing body) storing the pigment ink is left for a long period of time, the pigment settles in the ink tank or the ink pack. As a result, the concentration of the pigment in the ink tank or the ink pack varies depending on the height, leading to a nonuniform concentration state.
If the concentration is not uniform in the ink tank or the ink pack, there is a risk that high-concentration ink with a pigment concentration that is higher than in the uniform concentration state is supplied to the inkjet printer. If the high-concentration ink is supplied to the inkjet printer, print density is increased, and deterioration of image quality occurs, in some cases. In addition, because an increase in pigment concentration increases the viscosity of the pigment ink, if the high-concentration ink is supplied to the inkjet printer, clogging or the like easily occurs in the ink nozzle of the inkjet head.
In JP-A-2005-7855, a tubular ink stirring chamber is provided in an ink tank that is mounted to an inkjet printer. The ink stirring chamber extends upward from the bottom portion of the ink tank, and liquid inflow ports are formed at a plurality of positions at different heights. In the case where the concentration varies depending on the height in the ink tank, ink of different densities flows into the ink stirring chamber from the plurality of liquid inflow ports that are positioned at different heights. As a result, pigment ink with different concentrations undergoes convection and becomes mixed in the ink stirring chamber, and is supplied to the inkjet printer. Therefore, even in the case where the concentration is nonuniform in the ink tank, it is possible to avoid the supply of pigment ink with a predetermined concentration or higher to the inkjet printer.
An ink supply port (liquid supply port) for supplying ink to the inkjet printer is provided in the ink tank or the ink pack. In JP-A-2005-7855, the ink supply port is provided in the bottom portion of the ink tank, and the lower end of the ink stirring chamber is connected to the ink supply port. Here, in the case of applying the structure of JP-A-2005-7855 to an ink tank or an ink pack having the ink supply port provided in the upper portion thereof, there is a risk that the convection of ink in the ink stirring chamber is insufficient, and high-concentration ink and low-concentration ink are supplied without being sufficiently mixed.
For example, in the case where printing in a small amount and stopping printing are repeatedly performed, low-concentration ink flows into the ink stirring chamber at the upper portion thereof from the liquid inflow ports, and is supplied from the upper end of the ink stirring chamber to the ink supply port without being sufficiently mixed with high-concentration ink that flows into the ink stirring chamber at the lower portion thereof from the liquid inflow ports. At the lower portion of the ink stirring chamber, most of the pigment settles again, because the printing is stopped before the high-concentration ink undergoes convection and becomes mixed with the low-concentration ink at the upper portion of the ink stirring chamber. As a result, when the ink in the ink tank or the ink pack becomes low, there are risks that the high-concentration ink is supplied to the inkjet printer, and deterioration of printing quality, ink nozzle clogging and the like occur.